The following quote is taken from Is Jesus the Only Savior? by James R. Edwards pages 29-30
John Crossan believes that Jesus was illiterate. This, of course, contradicts the New Testament, for there we are told that Jesus read from Isaiah before preaching in the synagogue of Nazareth (Luke 4:16-20). Crossan puts forth the following argument for his conclusion: He begins by saying that according to Mark 6:3, Jesus was a tekton. The most common English rendering of tekton is "builder," or "carpenter," but Crossan takes the term not as a description of a trade, but as a description of a group of low-caste peasant expendables. He then states that 95-96% of Jews in first-century Palestine were illiterate; hardly any of the remaining 4-5% would have come from this low class. Here, then, is his conclusion: "[The stories that Jesus was literate] must be seen clearly for what they are: Lukan propaganda rephrasing Jesus' oral challenge and charisma in terms of scribal literacy and exegesis."12See also my blogpost: Did Jesus Speak Multiple Languages?
I argue that Crossan is wrong on this point, and here are my reasons why: All Greek-English lexicons render tekton as "carpenter," a reference to a trade, not to a social class.13 Moreover, we know that manual labor was not a derogatory distinction in Jewish Palestine, in contrast to Crossan's insinuation that it was. The Mishnah, for example, places the teaching of a manual trade to one's son on a par with teaching him Torah.14 Obviously, in the Jewish world anything analogous to Torah was clearly honorable. Now, it is hard for me to imagine that the commandment to teach one's son Torah would result in a 95% illiteracy rate among the Jewish population. Consider the Jewish literature produced by the Roman period: not only the entire Old Testament, but also the New Testament, Apocrypha, Pseudepigrapha, the Dead Sea Scrolls, Josephus, the Bar Kokhba literature, the Mishnah, and the Oxyrhynchus Papyri. These are immense bodies of literature; in the last, the Oxyrhynchus Papyri, some fifty thousand documents exist! Would a literary achievement so extensive have been produced for a 3-5% reading population? Further, if Crossan were right about Jesus' illiteracy, why would Luke have intentionally lied about it? After all, if 95% of the population were illiterate, there would be no reason to make Jesus literate.15
14. "A man should always teach his son a cleanly craft" (Qiddushin 4:14); "At five years old [one is fit] for the Scripture, at ten years for the Mishnah" (Aboth 5:21); "Above all we pride ourselves on the education of our children, and regard as the most essential task in life the observance of our laws..." (Josephus, Against Apion 1.60); "[The Law] orders that [children] be taught to read, and shall learn both the laws and the deeds of the forefathers..." (Josephus, Against Apion 2.204).
15. See A. Millard, "Literacy in the Time of Jesus," Biblical Archaeology Review 29/4 (2003): 37-45, who concludes that "writing and reading were widely practiced in the Palestine of Jesus' day." Further, G. Dalman, Jesus—Jeshua: Studies in the Gospels, trans. P. Levertoff (New York: KTAV, 1971), 36-37, leaves virtually no doubt that Jesus was literate.